Nividia-smi not working

I installed nvidia-driver for ubuntu 18.04 which runs on my notebook. But I am unable run the nvidia-smi command which shows NVIDIA-SMI has failed because it couldn’t communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running..
I attached bug report file for your reference as well.
nvidia-bug-report.log.gz (118.6 KB)